Moisture crosslinking elastomer composition

Abstract

The invention relates to moisture cross-linking compositions containing (A) 100 parts per weight of a silane-terminated polydiorganosiloxane-urea/urethane copolymer of general formula (1), and (B) between 0.1 and 20 parts per weight of silane of general formula (3): Ω-(CH 2 ) e —Si(R 2 ) 3-f (CH 3 ) f , in which R, X, A, Y, D, B, W, n, a, b, c, d, Ω, R 2 , e and f are defined as per claim 1.

1. A moisture-crosslinkable composition comprising
 (A) 100 parts by weight of at least one silane-terminated polydiorganosiloxane-urea/urethane copolymer of the general formula 1                  
 
  in which 
 R is a monovalent C 1-20  hydrocarbon radical optionally substituted by fluoro or chloro, 
 X is a C 1-20  alkylene radical in which nonadjacent methylene units are optionally replaced by —O—, 
 A is an oxygen atom or an amino group —NR′—, 
 R′ is hydrogen or a C 1-10  alkyl radical, 
 Y is a C 1-20  hydrocarbon radical optionally substituted by fluoro or chloro, 
 D is a C 1-700  alkylene radical in which nonadjacent methylene units are optionally replaced by —O—, —COO—, —OCO—, or —OCOO— groups, said alkylene radical optionally substituted by fluoro, chloro, C 1 –C 6  alkyl or C 1 –C 6  alkyl ester, 
 B is a radical of the formula 2
   -Z-Si(R 1 ) m (R″) 3-m   (2) 
 
 Z is a methylene radical, 
 R 1  is a monovalent C 1-12  hydrocarbon radical optionally substituted by fluoro or chloro, 
 R″ is a moisture-reactive radical selected from the group consisting of C 1 –C 4  alkoxy, C 1 –C 20  acyl, C 1 –C 6  alkylaminooxy, C 1 –C 6  alkyloximo, and mixtures thereof, 
 W is a radical B or hydrogen, 
 m is 0, 1 or 2, 
 n is an integer from 1 to 300, 
 a is an integer which is at least 1, 
 b is 0 or an integer from 1 to 30, 
 c is an integer from 1 to 30, and 
 d is 0 or 1, with the proviso that the composition of the units is chosen such that the copolymer possesses a melting point in the range of 30° C. to 200° C., and 
 (B) from 0.1 to 20 parts by weight of at least one silane of the formula 3
   Ω-(CH 2 ) e —Si(R 2 ) 3-f (CH 3 ) f   (3) 
 
 where 
 Ω is a moiety selected from the group consisting of —NHR 3 , —NR 3 —(CH 2 ) g —NHR 3 , acryloyl, methacryloyl, OCN, —SH, glycidyloxy, and chloro, 
 R 3  is hydrogen or an optionally halogen-substituted C 1-18  hydrocarbon radical, 
 R 2  independently are methoxy or ethoxy group, 
 e is 1 or 3, 
 f is 0 or 1, and 
 g is from 1 to 10. 
 
     
     
       2. The moisture-crosslinkable composition of  claim 1 , wherein polydiorganosiloxane blocks in copolymer (A) have a molecular weight Mw of from 500 to 30,000. 
     
     
       3. The moisture-crosslinkable composition of  claim 1 , wherein R are methyl, phenyl, or some R are methyl and some R are phenyl. 
     
     
       4. The moisture-crosslinkable composition of  claim 1 , wherein A is an amino group. 
     
     
       5. The moisture-crosslinkable composition of  claim 1 , wherein R″ is a methoxy or ethoxy radical, or wherein some R″ are methoxy and some R″ are ethoxy. 
     
     
       6. The moisture-crosslinkable composition of  claim 1 , wherein at least one Ω is a moiety selected from the group consisting of —NHR 3 , —NR 3 —(CH 2 ) g —NHR 3 , and glycidyloxy. 
     
     
       7. A one-component hotmelt adhesive which is moisture-crosslinking by way of silane end groups, comprising at least one moisture-crosslinkable composition of  claim 1 .